1. Field of the Invention
This invention relates to a novel aniline-resorcin-formaldehyde copolycondensation product, and more particularly to a novel adhesive composition which well adheres fibrous material to rubber and is less in the degradation of adhesion degree even under high temperature use condition.
2. Related Art Statement
It is well-known that a condensate of phenol and formaldehyde is used as a starting material of an adhesive composition for cords as a reinforcement for rubber. For instance, Japanese Patent Application Publication No. 46-11,251 discloses a reaction product of resorcin and p-chlorophenol. Furthermore, U.S. Pat. No. 3,318,750 discloses a reaction product of resorcin and triallyl cyanurate and formaldehyde. Moreover, U.S. Pat. No. 3,698,935 discloses a reaction product of aniline and resorcin and formaldehyde and also discloses that an adhesive composition consisting of the above reaction product, formaldehyde and rubber latex is useful for a single dip system on polyester fibers.
The aniline-resorcin-formaldehyde reaction product disclosed in U.S. Pat. No. 3,698,935 is a liquid resin obtained through two-stage condensation, wherein aniline is at least about 1/20 mol per 1 mol of resorcin and aldehyde is about 3/10 to 8/10 mol per 1 mol of resorcin and aniline is about 1/10 to 11/10 mol per 1 mol of aldehyde. In such a reaction product, the range of the mol number of aniline per 1 mol of resorcin is wide and includes a region not effective for the improvement of adhesion force as a starting material of an adhesive for polyester fibers.
Furthermore, a sum of mol number of aniline and mol number of resorcin per 1 mol of formaldehyde is within a range of 1.35 to 4.4, so that it is anticipated that a fairly large amount of aniline and resorcin not connected through methylene chain are contained in the reaction product, which is considered to impede the enhancement of adhesion. As seen from Examples of this patent, the reaction product is a viscous liquid, which is unfaborable from a viewpoint of the weighing operability in the production of the adhesive composition. Further, since the solid content of the product is not 100%, there is a problem on the weighing accuracy of effective component for adhesion. Moreover, the above patent does not disclose the degree of adhesion force and heat resistant adhesion force at all, so that the degree of the effect on adhesion is not clear.